TWI454832B - Method for inspecting and judging photomask blank or intermediate thereof - Google Patents

Description

Blank mask (Photomask blank) or its manufacturing intermediate inspection method, and methods for determining its advantages and disadvantages

The present invention relates to a blank mask used as a mask raw material for microfabrication of a semiconductor integrated circuit, a CCD (Charge Coupled Device), a color filter for an LCD (Liquid Crystal Display Element), a magnetic head, or the like, or an intermediate thereof. The method of inspection and the method of determining its merits and demerits.

In recent years, in semiconductor processing, especially with the high density of large-scale integrated circuits, the miniaturization of circuit patterns has become more and more necessary, and the wiring patterns for forming circuits have been miniaturized and composed of unit cells. The requirements for the miniaturization technique of the contact via pattern of the wiring between the layers of the (cell) are becoming higher and higher. Therefore, even in the manufacture of a photomask for writing a circuit pattern using photolithography which forms the wiring pattern or the contact via pattern, it is required to write a finer and correct circuit along with the above miniaturization. Graphic technology.

In order to form a finer pattern, when a mask and an optical system are used to illuminate a pattern on a photoresist film, if the shape of the mask is changed, the positional accuracy of the obtained image is lowered to cause a defective product, and it has been known that in order to solve the problem. The shape of the substrate of the photomask must be controlled (Patent Document 1: JP-A-2003-50458). It is suggested in the report that, as a substrate for fabricating a photomask, by using a specific surface shape, the surface shape change of the photomask when it is affixed to the reticle stage of the exposure machine can be suppressed.

In the past, the flatness of a transparent substrate for a photomask or a blank mask has been emphasized. When an optical film such as a light-shielding film or a aligning film is formed on a transparent substrate for a photomask, the shape of the substrate is not changed. In the manner of controlling the stress of the optical film, there is a large number of reports on how to control the "bending", that is, the shape change of the surface of the substrate (for example, Patent Document 2: JP-A-2004-199035).

On the other hand, in addition to the above-described problem of the shape of the substrate, in the pattern size control by the optical film such as the semiconductor circuit pattern written on the photomask to be used, it is required to reduce the size of the image to be used. There are very high heights. For example, a light-shielding film formed of a chromium material used in the past is difficult to control etching of a portion during etching processing in order to obtain a mask for obtaining a pattern having a minimum line width of 65 nm or less, particularly 50 nm or less. The coarse density of the pattern thus to be drawn becomes a problem of different trimming dimensions, and there is a clear problem of the so-called coarse density dependence of the pattern. On the other hand, in JP-A-2007-241060 (Patent Document 3), it has been clarified that the use of a material containing a transition metal in a light-shielding film can improve the problem of the coarse density dependency, and a very thin chromium is proposed. A method of processing a light-shielding film as an etching mask. In this patent, it is suggested that a reticle that is dimensionally controlled with extremely high precision can be manufactured by using a ruthenium material that can contain a transition metal as an etch mask.

However, the size control required for the photomask used in photolithography having a minimum size of 45 nm or less as the above-described semiconductor circuit pattern has an extremely high height, and it has been clarified that the use of a transition metal can be used for the light shielding film. When the material is produced by using an etched mask film made of a chrome-based material, it has become almost unrelenting.

Therefore, photolithography for forming a pattern having a minimum size of 45 nm or less is manufactured, for example, in a double pattern (refer to Non-Patent Document 1: Proceedings of SPIE, Vol. 6153, pp. 615301-1 to 19 (2006). In the case of a photomask used in photomicrography where position control is required for higher precision, if the reliability of the existing accuracy is not obtained, the yield of the mask manufacturing cannot be improved.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2003-50458

[Patent Document 2] JP-A-2004-199035

[Patent Document 3] JP-A-2007-241060

[Patent Document 4] Japanese Patent Publication No. 7-140635

[Patent Document 5] JP-A-2007-241065

[Patent Document 6] JP-A-63-85553

[Non-patent literature]

[Non-Patent Document 1] Proceedings of SPIE, Vol. 6153, pp. 615301-1~19 (2006)

The present invention has been made to solve the above problems, and an object thereof is to provide a blank mask for an optical functional film such as a light shielding film or a phase shift film which is required to be processed with high precision, and to ensure that it does not become a size during processing. A blank reticle for changing the surface shape of the cause of the error or a method for inspecting the intermediate thereof, and a method for determining the merits and demerits thereof.

As described above, as a method for controlling the shape of the mask and the blank mask which do not cause deterioration of the depth of focus when the mask is used, it is possible to prevent the shape of the substrate for the mask from being changed before and after the film formation of the optical film. In the optical film such as a light-shielding film or a phase-shift film, a film having a small stress is used (for example, Patent Document 2: JP-A-2004-199035).

However, the inventors of the present invention have conducted a more detailed discussion on the change in the surface shape during the processing of the blank mask due to the cause of the positional error of the mask, and found that the film can be imparted to the light-shielding film when the light-shielding film is formed. A light-shielding film having a surface shape in which the surface of the substrate in front of the film is extremely close to the surface shape, that is, a so-called light-shielding film of a blank mask which can be formed by a light-shielding film which is almost free from the conventional stress, although the stress of the light-shielding film is considered It is low, but in the end there will still be deformation of the surface shape, resulting in a decrease in positional accuracy with processing.

In order to improve the reliability of the position and size of the mask, in the case of photolithography for mask processing, it is necessary to form a pattern for forming the shading portion, etc. The position of the photoresist pattern (the position here does not mean the relative position on the surface of the blank mask, but means that, for example, the center point of the main surface of the blank mask is placed at the origin, so that the least square plane of the main surface is parallel to A pattern such as a light-shielding portion of the mask that has been trimmed is formed at a position where the space coordinates in the XY plane are formed. However, if the surface shape is changed at the time of etching, a positional shift occurs.

Therefore, the present inventors thought that it is necessary to perform the following inspection in order to obtain a blank mask of higher reliability. That is, it is considered necessary to compare the manufacturing surface of the blank mask or the blank mask to the outer surface shape before and after peeling off the optical functional film such as the light-shielding film formed thereon.

For example, when there is only a binary mask blank for forming a light-shielding film having a reticle with a bright pattern, the inspection can be performed by the following method.

(1) A plurality of blank masks having a light-shielding film are produced under certain conditions.

(2) One or more samples were taken from the blank mask manufactured as a sample.

(3) The surface shape of the sample was measured.

(4) The substrate for the mask (transparent substrate) from which the film including the light shielding film is removed is the outermost surface.

(5) The surface shape of the obtained substrate for a mask (transparent substrate) was measured.

(6) Comparing the surface shape data obtained in (3) with the surface shape data obtained in (5), the above-mentioned change is not specified as the pass.

It has been found that if the blank mask or its manufacturing intermediate is inspected by such methods, according to the obtained accuracy, on the contrary, based on the inspection result, a blank mask of the blank mask can be obtained by film formation of the optical functional film. The manufacturing characteristics can be reflected in the manufacture of the blank mask or its manufacturing intermediate. Moreover, after determining the surface shape according to the shape of the actual processing, the surface shape which is manufactured under the same conditions can be ensured that the surface shape during processing does not change. A higher degree of reliability is obtained, thus completing the present invention.

Accordingly, the present invention provides the following blank mask or method for inspecting the same and manufacturing method thereof.

Patent Application No. 1: A method for inspecting a blank mask or a manufacturing intermediate thereof, which is to inspect a blank mask or an intermediate thereof by evaluating stress of a film constituting a blank mask or an intermediate thereof. The method is characterized in that the method comprises the steps of: (A) measuring a surface shape of a blank mask having a film of a stress inspection object or a manufacturing intermediate thereof, and (B) a step of removing the film of the inspection object, And (C) measuring the surface shape of the film-treated substrate to which the inspection object is removed, thereby obtaining the blank mask before the film removal of the inspection object or the intermediate thereof, and the film after the film removal of the inspection object The surface shape of both of the substrates was processed, and the stress of the film to be inspected was evaluated by comparing the surface shapes.

The inspection method of the first aspect of the invention, wherein the film to be inspected is one or more selected from the group consisting of a phase shift film, a light shielding film, an etching mask film, and an etching stopper film.

Patent Application No. 3: The inspection method of claim 1 or 2, wherein the blank mask or the intermediate system for manufacturing the same, in the manufacturing process thereof, undergo a film constituting the blank mask or the intermediate thereof The step of giving energy to the winner.

The inspection method according to any one of claims 1 to 3, wherein the blank mask or the intermediate system for manufacturing the same is further processed by laminating other films while processing the mask. Further, before the step (A), the other film is laminated on the film to be inspected, and energy corresponding to the energy applied to the film to be inspected is applied to the film of the inspection object in advance. The surface shape was obtained by the treatment of the above steps (A) to (C), and the stress of the film to be inspected was evaluated by comparing the surface shapes.

Patent Application No. 5: The inspection method of claim 4, wherein the other film is a photoresist film.

The inspection method according to any one of claims 1 to 5, wherein the evaluation of the stress of the film of the inspection object is a blank mask before removing the film of the inspection object. The outermost surface of the substrate or the intermediate film thereof and the outer surface of the treated substrate after the film of the above-mentioned inspection object is completely removed from the blank mask or the intermediate thereof, and the following evaluation is performed:

(1) measuring each of the outermost surfaces by a surface shape measuring device, and obtaining XYZ three-dimensional coordinate data of the outermost surface,

(2) From the coordinate data obtained from each of the outermost surfaces, the least square plane of each outermost surface is obtained.

(3) making the relative position between the outermost surface coordinate of the blank mask or its manufactured intermediate body and its least square plane and the relative position between the outermost surface coordinate of the processed substrate and its least square plane fixed, so that the coordinates are Configure with the least square plane in the following manner:

(i) having both of the two least square planes on the XY plane of the XYZ three-dimensional imaginary space,

(ii) locating both the center of the area of the outermost surface of the blank mask corresponding to the least square plane of the former or the center of the area of the outermost surface of the processing substrate corresponding to the least square plane of the former, And

(iii) aligning the four corners corresponding to the outermost surface, and aligning the diagonal directions of the two regions corresponding to the outermost surface in a manner corresponding to the removal of the film corresponding to the inspection target overlapping,

(4) Within the coordinate data range of the above configuration, the coordinates of the X-value and the Y-value of the coordinate of the outermost surface of the blank mask or its manufactured intermediate body and the coordinates of the outermost surface of the processed substrate are blank. The Z value (Z ₁ ) of the outermost surface of the mask or its intermediate is determined as the difference (Z ₁ -Z ₂ ) from the Z value (Z ₂ ) of the outermost surface of the treated substrate,

(5) The sum of the absolute value of the maximum value of the Z value (Z _{1 -} Z ₂ ) and the absolute value of the minimum value is used as the amount of bending change, and the surface shape is compared by the amount of bending change.

Patent Application No. 7: A method for judging the merits and demerits of a blank mask or its manufacturing intermediate, characterized in that the blank mask or its blank mask is determined by the amount of bending variation obtained in the inspection method of claim 6 The advantages and disadvantages of manufacturing intermediates.

Patent Application No. 8: The method for judging the merits and demerits of the seventh application of the patent application is such that the value of the above-mentioned bending variation is 50 (nm) / L / 152 (mm) or less (only, L represents the length of the transparent substrate) Side length (mm) is considered a good product.

By using the blank mask of the present invention and the method for inspecting the intermediates thereof and the method for judging the advantages and disadvantages, the method for manufacturing the blank mask can be optimized, and the surface can be produced before and after the etching of the optical functional film or the processed functional film. A blank mask with a very low shape change, and a blank mask that ensures a reduction in dimensional error due to surface shape changes during the manufacture of the mask.

The invention is described in more detail below.

The mask size is 65 nm or less, especially the photomask used in photolithography below 45 nm, especially the mask used in the dual pattern mask requires extremely high mask precision. Therefore, the processing of the blank mask also requires extremely high processing accuracy.

As disclosed in Japanese Laid-Open Patent Publication No. 2003-50458 (Patent Document 1), a photomask for microfabrication has been required to have a transparent substrate having a specific shape that does not cause a shape change when the photomask is affixed to an exposure device. A light-shielding optical film is formed on a transparent substrate for a mask having a specific shape to obtain a blank mask, and the optical film is etched to form a photomask, thereby ensuring the yield of the mask. Therefore, even in the case of a light-shielding film or a phase-shift film, it has been conventionally used as a light-shielding film having a low stress, and a light-shielding film having a surface shape which is extremely similar to the surface shape of the substrate before film formation is pursued.

For example, on a substrate for a photomask, a film containing oxygen and nitrogen in molybdenum and tantalum is formed on a transparent substrate for a photomask to form a half-tone phase-shifting mask blank. In the case of a blank reticle having a relatively large compressive stress, by returning the illuminating flash to the shape of the original transparent substrate, a blank light having a semi-transparent phase shifting film having little stress on the previous reference can be manufactured. Cover (Patent Document 2: JP-A-2004-199035). However, as a result of investigation by the present inventors, it has been found that the above-described semi-transmissive phase-shifting film is removed by dry etching from the substrate, although the surface shape of the substrate used for film formation and the surface shape of the blank mask after the flash lamp irradiation are extremely Similarly, the surface shape is also changed to obtain a surface shape different from that of the transparent substrate used in film formation.

By the processing of the film constituting the blank mask, if the so-called bending change of the surface shape deformation occurs, a pattern position error as described below occurs when the photomask is manufactured.

In the case of the processing of the light-shielding film, the pattern processing is performed by using a pattern such as an electron beam to form a photoresist pattern for protecting the position where the light-shielding film pattern remains, and etching is performed using the obtained photoresist pattern to remove unnecessary portions. A light-shielding film, in particular, a photomask having a bright pattern (a pattern having a small residual area of the light-shielding film), in order to remove a large number of light-shielding films, if the light-shielding film has a large stress, the surface shape change as described above is strongly caused. When the shape of the surface is changed, the position of the photoresist and the position of the light-shielding film pattern are the same when the basic coordinates are set along the surface of the substrate. However, when the coordinates of the three-dimensional absolute coordinates are set in the space, for example, a blank is placed. When the center point of the surface of the mask is set to the origin, when the coordinates of the square of the blank mask surface are arranged on the XY plane and the coordinates are changed, the point A on the surface of the blank mask (a _x , a _y , a _z ) (but a _x = a _y ≠ 0) is not only displaced in the Z-axis direction but also becomes a coordinate displacement in the X-axis direction and/or the Y-axis direction.

In the case of a photomask used in photolithography to form a currently industrialized photoresist pattern having a pattern size of 50 nm or less, a 152 mm square mask is usually used, at the stage of completing the mask, if The designed position, that is, the position at which the electron beam is irradiated, is shifted by 50 nm in the Z-axis direction of the three-dimensional coordinate, and it cannot be said that the photomask has reliability.

In the present invention, when the blank mask or the intermediate body thereof is inspected by evaluating the stress of the film constituting the blank mask or the intermediate body thereof, the following steps are carried out:

(A) a step of measuring a surface mask of a blank mask having a film for stress inspection or a manufacturing intermediate thereof,

(B) a step of removing the film of the inspection object, and

(C) a step of measuring the surface shape of the treated substrate by removing the film of the inspection object,

Thereby, the surface shape of both the blank mask before the film removal of the object to be inspected or the intermediate body after the film removal, and the processed substrate after the film removal of the object to be inspected is obtained, and by comparing the surface shapes, the above-mentioned surface shape can be evaluated. Check the stress of the film of the object.

As described above, in order to obtain the reliability of the blank mask, it is not confirmed that the shape of the blank mask is not changed with respect to the shape of the substrate before film formation, but the manufacturing intermediate or blank mask of the blank mask forming the film is completed. Then, an optical functional film such as a light-shielding film, a phase shift film such as a semi-transmissive phase shift film, or a processing film such as an etching mask film or an etching stopper film is selected from a blank mask or a manufacturing intermediate thereof. More than one film to be inspected is removed by etching, and by confirming that the shape of the front and back surfaces is not changed, it is ensured that it is a blank mask corresponding to the high precision processing required at present.

In the case of the film to be inspected, that is, the film to be inspected, and the blank mask having the film or the intermediate of the production thereof, for example, the following may be mentioned. Here, a blank mask having two or more kinds of films is formed by sequentially forming a film to form a blank mask, but an intermediate product obtained by forming each film each time, and a film phase shift on the substrate alone A film, a light-shielding film, an etching mask film, an etching stopper film, and the like, that is, a film quality test substrate which individually evaluates the film quality of the film, is a manufacturing intermediate, and is an object of inspection of the present invention.

First, a blank mask having only a light shielding film is exemplified. This generally has a type having an upper layer containing an antireflection function layer and a lower layer containing a shading function layer, and a layer having an antireflection function on a layer having a shading function, but the inspection layer is before the removal of the light shielding film. The surface shape and the surface shape after the removal of the light-shielding film (in this case, the surface shape of the transparent substrate) were compared and inspected. By this inspection, if the surface shape does not cause a large change, it can be confirmed that the shape change is not caused when the photomask having a bright pattern is produced using the blank mask.

Further, the blank mask having only the phase shift film such as a semi-transmissive phase shift film may have a single layer or a plurality of layers, but in the same manner as described above, the phase shift film may be removed and inspected. Confirm that the phase shift mask is used to make a shape change.

A phase shift film having a semi-transmissive phase shift film or the like and a blank mask on which the light-shielding film is laminated can be confirmed as, for example, a dark pattern by removing only the light-shielding film (for example, a phase shift film) The phase of the substantially shaded portion of the pattern is not shifted in shape when the phase is shifted. Further, by simultaneously removing the light shielding film and the phase shift film and performing inspection, it was confirmed that the shape change was not caused when the phase shift mask was, for example, a bright pattern.

Further, the blank mask having the phase shift film and the light shielding film may be provided with an etching stopper film as a processing function film as an intermediate layer. In this case, only the etch stop film can be used as the inspection target, but usually the optical design is determined according to whether the etch stop film is the phase shift amount to which the phase shift film should be added. One part of the transfer film is equivalent to one part of the light-shielding film, so that it is determined whether or not the film is removed when the light-shielding film or the phase-shift film is removed. Further, if the film is relatively thin, it is not possible to sufficiently estimate whether or not the film is not completely removed, and the film may not be completely removed. In this case, if an optical functional film is provided under the etching stopper film (on the transparent substrate side), the optical functional film may be removed for inspection.

Further, in the optical functional film such as a light-shielding film described in JP-A-2007-241060 (Patent Document 3), an etched photomask film is formed on the film (generally referred to as an etched photomask film). As a part of the optical functional film, it is a part of the reticle, and it is used only as a processing auxiliary film on the film (the transparent substrate side) and is finally removed. In the invention, a blank mask which is a film of a processing function, which is referred to as an etched film, or a semi-transparent phase shift film, as described in JP-A-7-140635 (Patent Document 4). A blank mask for etching the photomask film is disposed on the optical functional film. When only the etching mask film was peeled off and examined, it was confirmed that the shape change was not caused when a mask such as a dark pattern was formed on the film provided under the etching mask. In this case, the optical functional film provided under the etching mask film may be removed for inspection if necessary.

Although the substrate is not deformed at the time of film formation, if the film is removed from the completed blank mask, the above phenomenon of the shape of the substrate to be removed is not completely understood, but it is presumed that the laminate is laminated. The film imparts energy, such as high energy light illumination or heating, for one reason. The film obtained by reactive sputtering using sputtering, in particular, by reactive sputtering, is usually stabilized by film formation, and is subjected to heat treatment after film formation. As described in Japanese Laid-Open Patent Publication No. 2004-199035 (Patent Document 2), even if a film having a large stress is heated by a usual heating device, the stress of the film itself cannot be completely released, but the stress is released by heating. In the range that is not in the range, the surface shape changes, and it is considered that it affects the reliability of the photomask used in the micro-shadowing of extremely fine patterns.

Therefore, the present invention is particularly effective for a blank mask or a manufacturing intermediate thereof, which is subjected to a step of imparting energy to a film constituting a blank mask or an intermediate thereof.

In addition, for the above-mentioned reason, the film to be inspected is not particularly formed into the film, but is particularly effective as a subject to the history of the processing of the light before the completion of the blank mask, for example, light irradiation or heating imparted to the film as needed. Further, in the case of more intensive inspection, for example, heating or formation of an effect of forming a photoresist pattern into a photomask is considered to be a processing history.

Therefore, in order to perform a more intensive inspection, for example, in a blank mask in which a photoresist film such as a laminated photoresist film is processed as another film, it is preferred that the other film be laminated on the film to be inspected, and other In the film processing, the energy applied to the film to be inspected by the application of energy by heating or the like is applied to the film to be inspected in advance, and then the surface shape of the blank mask having the film to be inspected or the intermediate body to be produced is measured. More specifically, it is preferable that the blank mask or the manufacturing intermediate thereof to which the energy is applied to the history when the resist pattern is formed is applied.

In this case, since the heating at the time of forming the photoresist pattern is lower than the heating used for the film stabilization after the sputtering film formation, and the time is shorter, it is considered that the influence is not so large, so if it is sputtered After the film is heated, the heating at the time of forming the photoresist pattern can be simply discarded. On the other hand, in the heating step in which the heating process is not increased more than the formation of the photoresist pattern after the sputtering film formation, etc., the possibility of heating due to the film formation of the photoresist is more likely. It is high, so it is better to increase the heating history when forming the photoresist pattern and check it.

The heating in the step of forming the photoresist pattern is usually performed by pre-exposure heating and post-exposure heating, but the treatment for increasing the heating history is preferably determined according to the photoresist pattern forming step. The heating step may be performed only once in the heating step or in the plurality of heating steps. Further, the temperature range may be about ± 20 ° C of the actual heating temperature in the step of forming the photoresist pattern, and the time may be appropriately set within a range of one-third to two times the total of the actual time in the step of forming the photoresist pattern. Further, if it is known in advance that the heating affects the deformation of the film to be inspected, the heat treatment here can be simplified.

Furthermore, the inspection method of the present invention can also be applied to a blank mask manufacturing intermediate or a film having a phase shift film, a light shielding film, an etching mask film, an etching stopper film, and the like separately formed on the substrate, that is, applicable. A film quality test substrate for evaluating the film quality of the films was individually evaluated. That is, since the blank mask is basically not a separate user for the bright pattern or the dark pattern, as will be described later, the optical functional film or the processing functional film constituting the blank mask is preferably substantially independently The shape of the surface does not change when processing. Therefore, when the conditions of the material or the layer structure of the film or the treatment for changing the stress are set, the film is formed by a method in which the surface shape of the substrate before the film formation is not changed, and the film is formed. In the inspection method of the invention, it is evaluated whether or not the surface shape after removal is changed when the film formed film is removed, and the film formation method is more effective in accordance with the result. Further, according to the method of the present invention, after the film formation, the processing history is added according to the subsequent processing steps, and the film is removed and inspected.

Further, in the case where a blank mask having a plurality of films is formed, even when a film is formed under a favorable condition for each film, when a heating history such as heating or patterning is added in a state in which each film is laminated, Since it is not necessarily the same as the case where the processing history is added to the processing history in the individual state of each film, in order to perform more precise inspection, it is also checked in the form of the final blank mask, that is, in the state in which all the films are formed. effective.

A blank mask which can advantageously use the inspection method of the present invention and a manufacturing intermediate thereof are those which can be used for manufacturing a lithography mask suitable for a pattern specification of 50 nm or less, and the above-mentioned light transmissive mask is used. Although an example is described, it is also applicable to a reflective mask represented by a mask for EUV.

As a substrate for a photomask (a substrate for a blank mask) used in the production of a transmissive mask, a quadrangular shape, in particular, a square is used, and a conventionally known substrate such as a synthetic quartz substrate which is transparent to the exposed light can be used. In the case of using the reticle as shown in Japanese Laid-Open Patent Publication No. 2003-50458 (Patent Document 1), it is preferable to have a shape which is not deformed by the shape of the substrate for the reticle by the exposure device or the like.

In the blank mask, a light-shielding film, a phase shift film, or both of the optical function films are formed on the substrate for the photomask, and further, the film may be processed to improve the processing accuracy during pattern processing. As an etching mask film, an etching stopper film or both of the film of the processing function.

In the case of having such a film structure, when both the light-shielding film and the phase-shift film are provided, the phase shift film and the light-shielding film are laminated in this order from the substrate side of the photomask.

Further, the etching mask film is used to improve the processing accuracy in the etching process of the outermost optical functional film (usually the above-mentioned light shielding film), and is usually provided on the outermost optical functional film.

Further, the etching stopper film for preventing the underlying film from being damaged during the etching of the upper film is provided between the substrate for the mask and the phase shift film, or between the phase shift film and the light shielding film. Either or both. However, in general, the film which exhibits the etching stopper function is generally used as a layer of a portion of the substrate side of the mask for the phase shift film or a layer of a portion of the light shielding film side, and further serves as a phase of the light shielding film. In the case where the film is one of the layers on the side of the film, it is not necessary to use a separate film as the etching stopper film. Therefore, the etch stop film can also be treated as part of the phase shift film or as part of the light shielding film.

The phase shifting film of one of the above optical functional films is typically a semi-transmissive phase shifting film, and a number of examples are known, generally consisting of a single layer, a plurality of layers or a layer of material having an inclined composition. The material to be used is a light element such as oxygen or nitrogen which is contained in a material containing a transition metal (for example, see Patent Document 4: Japanese Laid-Open Patent Publication No. Hei No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No The transition metal contains a layer of light elements such as oxygen or nitrogen as a layer.

When the phase shift film is a whole of the film, since a considerable amount of the above-mentioned light element is added, it is a film having a compressive stress at the stage of film formation. In the present invention, when the film itself has a large compressive stress in the state in which the film is formed, there is a case where the surface shape at the time of removing the phase shift film is unqualified, and it is necessary to release the stress. The situation of processing. There are various reports on the stress release method (for example, Patent Document 2: JP-A-2004-199035), and any of basically known methods can also be used.

When a semi-transmissive phase shift film is used as the phase shift film, the film may be a single layer film, a multilayer film or a film having a tilted composition, or the like, and a material containing a transition metal may be used as the material of the semi-transmissive phase shift film. In this case, an alloy of a transition metal and ruthenium, a transition metal, ruthenium, and a transition metal ruthenium compound selected from the group consisting of oxygen, nitrogen, and carbon may be specifically exemplified, preferably containing a transition metal, ruthenium, and oxygen and/or A transition metal ruthenium compound of nitrogen. More specific examples of the transition metal ruthenium compound include transition metal ruthenium oxide, transition metal ruthenium nitride, transition metal ruthenium oxynitride, transition metal ruthenium oxide, transition metal ruthenium nitride, and transition metal ruthenium. Oxynitride carbides, etc. Further, one or more selected from the group consisting of titanium, vanadium, cobalt, nickel, zirconium, hafnium, molybdenum, niobium, tantalum and tungsten is a suitable material for the transition metal, but is preferably a molybdenum in terms of dry etching processability. . The ruthenium material containing the transition metal is preferably used in an amount of 10 atom% or more and 95 atom% or less, oxygen of 0 atom% or more, 60 atom% or less, and nitrogen of 0 atom% or more and 57 atom% or less. 0 atom% or more and 20 atom% or less, and the transition metal is a material having a composition selected from the range of 0 atom or more and 35 atom% or less, particularly preferably 1 atom% or more and 20 atom% or less. The above materials are selected in a so-called single layer, multilayer film configuration, or film thickness, and a desired specific transmittance and phase shift amount.

When the self-finished blank mask or its manufacturing intermediate body is removed from the phase shifting film to perform the inspection of the amount of bending change, it is preferable to use a method similar to the etching method used in etching the phase shifting film during the mask processing. In the case of a material containing a transition metal, dry etching using a fluorine-based etching gas is preferably used.

As the light-shielding film which is one of the optical functional films, a known material such as a chrome-based material or a ruthenium-containing material which may contain a transition metal or a combination of these layers is used. A general light-shielding film is composed of a multilayer film formed by a light-shielding layer that strongly suppresses light transmission and an anti-reflection layer for reducing reflectance or a film having an inclined composition, and the anti-reflection layer is provided only on the surface side of the light-shielding layer or It is on both the surface layer side of the light-shielding film and the substrate side of the photomask.

The light-shielding layer in the above film is for strongly suppressing light transmission without adding a light element (oxygen, nitrogen, carbon, etc.) or a film having a lower light element content. Conversely, the anti-reflection layer requires a certain degree of light. Transmissive, so it has a higher light element content than the light-shielding layer. Therefore, the light shielding layer tends to have tensile stress, and the antireflection layer tends to have compressive stress. Therefore, in the same manner as the phase shift film described above, the stress is released or the stress of the light shielding layer is balanced with the stress of the antireflection layer, as in the case of the phase shift film. It is designed to have no large stress as a whole of the film.

When the light-shielding film material is a chromium-based material, a chromium monomer or a chromium compound containing at least one selected from the group consisting of oxygen, nitrogen, and carbon is preferably exemplified, and the chromium-based material is preferably used in an amount of 30 atom% from chromium. a material having a composition selected from the range of 100 atom% or less, oxygen of 0 atom% or more, 60 atom% or less, nitrogen of 0 atom% or more, 50 atom% or less, and carbon of 0 atom% or more and 20 atom% or less. . As described above, when the chromium content is large, tensile stress is imparted, and when the content of light elements such as oxygen, nitrogen, and carbon is large, compressive stress is applied. Therefore, it is preferable to select a film structure in consideration of these.

Further, when a material containing a transition metal is used as the light-shielding film material, an alloy of a transition metal and ruthenium, a transition metal, ruthenium, and a transition metal ruthenium compound selected from the group consisting of oxygen, nitrogen, and carbon may be specifically exemplified. It is preferably a transition metal ruthenium compound containing a transition metal, ruthenium, and oxygen and/or nitrogen. More specific examples of the transition metal ruthenium compound include transition metal ruthenium oxide, transition metal ruthenium nitride, transition metal ruthenium oxynitride, transition metal ruthenium oxide, transition metal ruthenium nitride, and transition metal ruthenium. Oxynitride carbides, etc. Further, one or more selected from the group consisting of titanium, vanadium, cobalt, nickel, zirconium, hafnium, molybdenum, niobium, tantalum and tungsten is a suitable material for the transition metal, but is preferably a molybdenum in terms of dry etching processability. . The ruthenium material containing the transition metal is preferably used in an amount of 10 atom% or more and 95 atom% or less, oxygen of 0 atom% or more, 60 atom% or less, and nitrogen of 0 atom% or more and 57 atom% or less. 0 atom% or more and 20 atom% or less, and the transition metal is a material having a composition selected from the range of 0 atom or more and 35 atom% or less, particularly preferably 1 atom% or more and 20 atom% or less. Further, generally, when the total content of the film composition is large, tensile stress is imparted, and when the content of other elements is large, compressive stress is applied. Therefore, it is preferable to select the structure of the film.

The above-mentioned material is a film which combines a light-shielding film and another light-absorbing film when the light-absorbing film other than the light-shielding film is not a light-absorbing film such as a semi-transmissive phase-shift film, and which is combined with another light-absorbing film. The light absorption coefficient is 2.0 or more, preferably 2.5 or more, and is selected in consideration of the film configuration or the film thickness.

When the light-shielding film is removed from the completed blank mask to perform the inspection of the amount of change in the bending amount, it is preferable to use a method similar to the etching method used in etching the light-shielding film during the mask processing. In the etching of a film made of a ruthenium compound containing a transition metal, a dry etching method using a fluorine-based etching gas is generally used. However, when etching using a chlorine-based etching gas, a chlorine-based method may be used. A method of etching a gas. Further, in the case of a film made of a chromium-based material, a method of using a chlorine-based dry etching gas to which oxygen is added is preferred.

The etching mask film of one of the processing functional films is used as a protective portion for protecting the film to be etched when etching a film (generally a light shielding film) formed on the substrate side of the mask for etching the mask film. The function of the etched reticle and the film that is completely stripped before the reticle is completed. Therefore, when functioning as an etching mask, a material which has high etching resistance to etching conditions suitable for etching of a protective film and which can be removed without damaging the film to be protected is used. When a material containing a transition metal is used as the protective film, a chromium-based material is preferably used (refer to Patent Document 3: JP-A-2007-241060), and when a chromium-based material is used as the protective film, it is preferably used. A material containing a transition metal (refer to Patent Document 6: JP-A-63-85553, etc.).

Since the etching mask film can be an extremely thin film of 1 to 5 nm depending on the material selection, it is not necessary to pay attention to the conventional film stress, but in order to perform control with higher precision, stress control is preferably performed. As for the control method, as in the case of the above-mentioned light shielding film, the stress releasing treatment may be performed, or a layer having a lighter element and a smaller layer in the above materials used in etching the photomask film may be used in combination. method. Further, the peeling of the film is also the same as in the case of the light-shielding film, and an appropriate method is selected for the compounding material.

On the other hand, the etch stop film, as described above, can be treated as a part of the phase shift film or a part of the light shielding film, and a preferred material thereof is exemplified by the phase shift film and the light shielding film described above. The same as those exemplified, the etching can also be applied to those who apply to individual films.

As described above, each of the optical functional film and the processed functional film constituting the blank mask of the present invention preferably independently controls the stress of the individual film, but on the other hand, it is designed in such a manner that stress is hardly generated even when the film is formed as described above. The film formed film also has a surface deformation when the film is removed. Therefore, when removing the film from the blank mask, it is preferable to set a combination of films having a shape deformation not higher than the reference, and it is preferable to combine the films having no large stress, and then to evaluate the surface shape change during the entire process of manufacturing the mask. The move is selected and the preferred combination is selected.

The comparison between the surface shape of the blank mask or the intermediate body thereof before the film removal of the inspection object and the surface shape after the film removal of the inspection object can be carried out as follows.

For example, an optically scanable surface (a transparent substrate surface, a film-formed film surface (a blank mask or a surface thereof), or a transparent substrate or a film surface of a processed substrate exposed after removal of a film to be inspected) is used. The surface analysis device (surface shape measuring device) of the shape was measured for the surface shape of the blank mask or the intermediate body before the film removal. Next, after the film of the inspection object is removed, measurement data of the surface shape after the film is removed is obtained. The difference between these two surface shapes can generally be evaluated as the amount of bending variation. The amount of bending change, if it is a method that can be reasonably defined, can be determined by any method, and can be judged as a reference value of a good product, and can be set according to the accuracy of the reticle to be used, for example, by the following method In comparison, the merits of the blank mask or its manufacturing intermediate can be determined.

The outermost surface of the blank mask or the intermediate body on which the film is to be removed, and the outermost surface of the processed substrate after the film of the inspection object is completely removed from the blank mask or the intermediate thereof,

(1) measuring each of the outermost surfaces by a surface shape measuring device, and obtaining XYZ three-dimensional coordinate data of the outermost surface,

(2) From the coordinate data obtained from each of the outermost surfaces, the least square plane of each outermost surface is obtained.

(3) making the relative position between the outermost surface coordinate of the blank mask or its manufactured intermediate body and its least square plane and the relative position between the outermost surface coordinate of the processed substrate and its least square plane fixed, so that the coordinates are Configure with the least square plane in the following manner:

(i) having both of the two least square planes on the XY plane of the XYZ three-dimensional imaginary space,

(ii) locating both the center of the area of the outermost surface of the blank mask corresponding to the least square plane of the former or the center of the area of the outermost surface of the processing substrate corresponding to the least square plane of the former, And

(iii) aligning and overlapping the two corners corresponding to the outermost surface in such a manner that the two corners corresponding to the outermost surface are aligned so that the film corresponding to the outermost surface is aligned before and after the film is removed.

(4) Within the coordinate data range of the above configuration, the coordinates of the X-value and the Y-value of the coordinate of the outermost surface of the blank mask or its manufactured intermediate body and the coordinates of the outermost surface of the processed substrate are blank. The Z value (Z ₁ ) of the outermost surface of the mask or its intermediate is determined as the difference (Z ₁ -Z ₂ ) from the Z value (Z ₂ ) of the outermost surface of the treated substrate,

(5) The sum of the absolute value of the maximum value of the Z value (Z _{1 -} Z ₂ ) and the absolute value of the minimum value is taken as the amount of bending change.

More specifically, first, the surface of the blank mask before the film removal or the intermediate surface of the manufacturing intermediate thereof is measured by using a surface shape measuring device such as an optical system (in this case, the surface of the film to be inspected). The surface shape is made into the XYZ three-dimensional coordinate data (surface chart) of the outermost surface, and the least square plane is obtained. Then, all the films to be inspected are removed by the removal conditions (peeling conditions) used in the basic processing, and the outermost surface of the substrate after the film removal of the object to be inspected is measured in the same manner (in this case, the film to be inspected) The surface shape of the adjacent film or the surface of the transparent substrate is made into the XYZ three-dimensional coordinate data (surface chart) of the outermost surface, and the least square plane is obtained.

Then, using the equipment such as the calculation device, the resulting coordinates and the least square plane are used to make the relative position between the outermost surface coordinate of the blank mask or its manufacturing intermediate body and its least square plane, and the outermost surface coordinate of the processing substrate and the minimum The relative positions between the square planes are arranged in the virtual space in such a manner that they are individually fixed (the outermost surface coordinates are integrated with the least square plane from which they are obtained), and all of the following conditions (i) to (iii) are satisfied.

(i) Arranging both of the two least square planes on the XY plane of the XYZ three-dimensional imaginary space.

(ii) locating both the center of the area of the outermost surface of the blank mask corresponding to the least square plane of the former or the center of the area of the outermost surface of the processing substrate corresponding to the least square plane Configuration.

(iii) aligning the four corners corresponding to the outermost surface, and aligning the diagonal directions of the two regions corresponding to the outermost surface in a manner corresponding to the removal of the film corresponding to the inspection target Overlap and configure.

This operation, if illustrated with reference to the figure, will be the blank surface mask shown in FIG. 1(A) or the outermost surface coordinate group 101 of its manufacturing intermediate body and its least square plane 102 as shown in FIG. 1(B). The outermost surface coordinate group 201 of the processing substrate and its least square plane 202 are disposed in the XYZ three-dimensional imaginary space as shown in FIG. 1(C). Moreover, the least square plane 102 and the least square plane 202 are disposed on the XY plane such that the two are on the same plane. Further, both the center of the region 102a corresponding to the outermost surface of the blank mask of the least square plane 102 or the intermediate body thereof and the center of the region 202a of the outermost surface of the processing substrate corresponding to the least square plane 202 are disposed to be located. The origin of the XYZ coordinate (i.e., the least square plane 102 and the least square plane 202 are arranged on the XY plane of Z=0). Furthermore, the four corners corresponding to the outermost surface region 102a and the four corners corresponding to the outermost surface region 202a are in a manner corresponding to before and after the film removal of the inspection object (the same angle corresponds to the same angle), so that The diagonal directions of the two regions corresponding to the outermost surface are aligned and arranged.

Next, as shown in FIG. 1(C), in the range of coordinate data to be arranged, the blank mask or the coordinates of the outermost surface of the manufacturing intermediate and the outermost surface of the processing substrate are consistent in the X value and the Y value. For each coordinate pair, the Z value (Z ₁ ) of the outermost surface of the blank mask or its intermediate is determined to be the difference (Z ₁ -Z ₂ ) from the Z value (Z ₂ ) of the outermost surface of the substrate. In this case, when Z ₁ > Z ₂ , the difference (Z _{1 -} Z ₂ ) becomes positive (+), and when Z ₁ < Z ₂ , the difference (Z _{1 -} Z ₂ ) becomes negative (-).

Therefore, the sum of the absolute value of the maximum value of the difference in Z values (Z _{1 -} Z ₂ ) and the absolute value of the minimum value is taken as the amount of bending change.

When it is a 152 mm (6 inch) square blank mask or an intermediate thereof, if the bending variation amount thus obtained is 50 nm or less, a double pattern exposure having a pattern for forming a minimum line width of about 25 nm can be obtained. Machining accuracy of the margin that can be used.

Further, even if it is a blank mask other than the size of the blank mask or its manufacturing intermediate, the allowable amount of the bending variation is proportional to the size of the blank mask or the intermediate thereof, and the value of the bending variation is 50 (nm). ) / L / 152 (mm) or less (only, L represents the long side length (mm) of the transparent substrate), and high processing accuracy can be obtained.

More simply, the coordinate data is for both the outermost surface of the blank mask and the outermost surface of the processing substrate, and the least square surface of the surface can be simply calculated, centered on the center of each outer surface, on a circle of radius R (nm) The coordinates of three or more points are used as the object, and the least square plane is obtained from the coordinates of the three or more points and the center point, and the amount of bending change can be evaluated in the same manner as described above. In this case, the criterion for the blank mask for forming the mask used in the double pattern exposure for forming a pattern having a minimum line width of about 25 nm is to display the value of the amount of bending change as follows: the following:

[Number 1]

As described above, it is possible to ensure high reliability of the positional accuracy of the photomask.

Further, according to the above method, the dimensional error caused when the blank mask is processed into a mask can be estimated by the stress of the optical functional film or the processed functional film which the blank mask obtained in the specific manufacturing step has. Then, when the sample to be inspected is acceptable, the above inspection can ensure that the blank mask manufactured by the above specific manufacturing steps in the same step as the sample used does not cause a dimensional error due to surface deformation generated during processing. At the same time, when a conventional blank mask is used, it is possible to prevent the occurrence of defective products due to dimensional errors.

[Examples]

The present invention will be specifically described below by showing examples, but the present invention is not limited to the following examples.

[Example 1]

(Manufacture of blank mask with semi-transmissive phase shift film)

Four substrates of a synthetic quartz reticle with a side length of 152 mm were prepared, and a film thickness of 76 nm was formed by using a sputtering method using argon gas and nitrogen gas and oxygen gas as a sputtering gas by using MoSi and Si as targets. MoSiON film (Mo: Si: O: N = 1: 4: 1: 4 (atomic ratio)).

(shape adjustment)

For the four blank masks in which the MoSiON film was formed, a xenon flash lamp having an irradiation width of 1 ^{- 10} msec was used, and the blank mask was irradiated with four different energies. Further, in the following, although the energy is displayed using the normalized value, the individual value is a value when the energy when 3175 V is applied is set to 1.

(Comparative of the surface shape of the substrate before film formation of the phase shift film and the surface shape of the blank mask for imparting high energy for adjusting the shape)

The surface of the substrate before the film formation of the semi-transparent phase shift film and the surface shape of the blank mask for imparting high energy for adjusting the shape are compared by the amount of change in bending (ΔTIR). This amount of change in bending (ΔTIR) was obtained as follows.

Using the optical surface shape measuring device (UltraFlat manufactured by Tropel Co., Ltd.), the surface shape of the individual blank masks subjected to the flash lamp after the film formation of the semi-transparent phase shift film was measured, and surface shape data (coordinates) were obtained. Next, the substrate surface shape data before the film formation of the individual semi-transparent phase shift film measured in advance was evaluated by the above methods (1) to (5), and the amount of change in bending (ΔTIR) was obtained. Further, ΔTIR is a deformation on the tensile stress side on the positive side. The amount of curvature (ΔTIR) of the surface shape of the blank mask after irradiation with the substrate for the mask used for the individual blank mask with respect to the surface shape of the phase shift film before film formation is shown in Fig. 2 .

(Removal of phase offset film)

The blank mask of the phase shift film having the above-described shape adjustment by irradiating the flash lamp with different energy is removed by dry etching using a fluorine-based etching gas under the following dry etching conditions.

RF1 (RIE): CW 54W

RF2 (ICP): CW 325W

Pressure: 5 mTorr

SF ₆ : 18sccm

O ₂ : 45sccm

(Compared with the surface shape of the blank mask before the phase shift film removal of the blank mask for shape adjustment and the surface shape of the removed substrate)

The surface of the treated substrate obtained by removing the phase shift film by dry etching described above was measured using an optical surface shape measuring device (UltraFlat manufactured by Tropel Co., Ltd.) to obtain data of the surface shape. The surface shape and the surface shape of the individual blank masks which were irradiated with the flash after the semi-transmissive phase shift film were formed were compared with the above-described method, and the amount of change in bending (ΔTIR) was obtained. The amount of change in bending is shown in Fig. 2.

As shown in Fig. 2, the high-energy line irradiation was performed and completely returned to the shape of the substrate before the film formation of the phase-shift film, and the irradiation of the irradiation energy of about 1.108 was estimated by extrapolation from the drawing in the figure. However, as can be seen from FIG. 2, the ΔTIR value generated by the phase-adjusted film removal due to the shape adjustment is similar to the operation of the phase shift mask processing by the bright pattern when the energy of about 1.108 is irradiated. The amount of change in bending produced by phase shift film removal is shown as a large positive value. Therefore, it is inferred that the phase shift film that irradiates the amount of the energy has a large tensile stress.

Further, from the drawing in the figure, it is estimated that there may be a one-time approximation between the ΔTIR display when the phase shift film is removed and the irradiation amount of the irradiation energy line, and the stress of the film that irradiates the flash lamp becomes zero when the energy of 1.017 is irradiated.

[Embodiment 2]

(filming of etched mask film)

In the same manner as in Example 1, a MoSiON film having a film thickness of 76 nm was formed on four substrates of a synthetic quartz mask having a side length of 152 mm (Mo: Si: O: N = 1: 4: 1: 4). (Atomic ratio)) The obtained substrate on which the MoSiON film was formed was further irradiated with an irradiation energy of 1.015 using the flash lamp irradiation apparatus described in Example 1.

Next, an etching mask film (film thickness: 7 nm) made of CrN was formed on the semi-transmissive phase shift film by using a DC sputtering apparatus. Ar and nitrogen were used as the sputtering gas, and the gas pressure in the chamber was adjusted to 0.05 Pa. Using Cr as a target, the substrate was formed while rotating at 30 rpm. The composition of the etching mask film was investigated by ESCA to be Cr:N=9:1 (atomic ratio).

Further, an etching mask film (film thickness: 7 nm) made of CrON was formed on the etching film made of CrN. Ar and nitrogen were used as the sputtering gas, and the gas pressure in the chamber was adjusted to 0.05 Pa. Using Cr as a target, the substrate was formed while rotating at 30 rpm. The composition of the etching mask film was investigated by ESCA to be Cr:N:O = 5.5:2:2.5 (atomic ratio).

Next, for the four substrates of the film-forming semi-transmissive phase shift film and the two etching mask films, the two sheets were heated at 200 ° C for 10 minutes (as heat treatment A), and the two sheets were heated at 150 ° C for 10 minutes (as heat treatment B). The etched reticle film is stabilized to obtain a transflective phase shift blank reticle having an etched reticle film.

Further, in the blank mask obtained above, each of the sheets treated under different heating conditions was heated at 150 ° C for 10 minutes (heat treatment C) in accordance with the heating operation by the step of forming a photoresist film.

The stress inspection of the film of the four blank masks obtained above was carried out as follows.

First, the surface shape of each of the four blank masks having the etching mask film was measured using a surface shape measuring device (UltraFlat manufactured by Tropel Co., Ltd.) to obtain surface analysis data. Next, after etching using chlorine-based dry etching conditions (Cl ₂ : 185 sccm, O ₂ : 55 sccm, He: 9.25 sccm), only the etching mask film was selectively removed from the blank mask.

Further, according to the method of the first embodiment, the surface shape of the blank mask before the removal of the mask film and the surface shape of the removed processed substrate (the substrate having the semi-transmissive phase shift film) are compared as a film stabilization operation. In the two blank masks which are heated at 200 ° C (heat treatment A), the stress of the etch mask film which is not further heated at 150 ° C for 10 minutes (heat treatment C) is compressive stress, by the film The amount of change in bending (ΔTIR) caused by the removal was 29 nm. Further, the stress of the etching mask film of the blank mask which was further heated at 150 ° C for 10 minutes (heat treatment C) was a compressive stress, and the amount of change in bending (ΔTIR) due to film removal was 28 nm.

On the other hand, as a film stabilization operation, in two blank masks which were heated at 150 ° C (heat treatment B), an etch mask film of a blank mask which was not further heated at 150 ° C for 10 minutes (heat treatment C) was used. The stress is a compressive stress, and the amount of change in bending (ΔTIR) caused by film removal is 38 nm. Further, the stress of the etching mask film of the blank mask which was further heated at 150 ° C for 10 minutes (heat treatment C) was a compressive stress, and the amount of change in bending (ΔTIR) due to film removal was 29 nm.

From the above results, it is found that the conditions for the heating stability of the etching mask film are such that the surface shape change at the time of film formation of the photoresist film is small at 200 ° C for 10 minutes, and processing reliability can be obtained.

Further, for the two sheets of the blank mask which were subjected to the above inspection and heated at 200 ° C for 10 minutes (heat treatment A), the etching mask film was removed according to the method of Example 1, and then the semi-transparent phase shift film was removed. And compare the surface shape before and after the removal of the semi-transparent phase shift film. In either case, the stress of the obtained transflective phase shift film is a compressive stress, and the amount of surface curvature change (ΔTIR) caused by film removal is 1 nm. Therefore, the amount of surface curvature change (ΔTIR) is 30 nm and 29 nm, respectively, when both the etching mask film and the semi-transmissive offset film are removed from the blank mask having the etching mask film and the semi-transmissive offset film. It can be confirmed that high positional accuracy can be obtained even when the blank mask is used to manufacture a semi-transmissive phase shift mask of a bright pattern.

In the above embodiment, the semi-transmissive phase shift film and the etching mask film are displayed. However, the processing film of the optical functional film or the etching stopper film other than the semi-transmissive phase shift film such as the light-shielding film can be similarly examined. The film stress was evaluated.

101. . . The most surface coordinate group of a blank mask or its manufacturing intermediate

102. . . The smallest square plane of the outermost surface of a blank mask or its manufactured intermediate

201. . . Processing the most surface coordinate group of the substrate

202. . . Processing the smallest surface of the substrate

102a, 202a. . . Equivalent to the most surface area

1 is a view for explaining a method for evaluating a change in surface shape before and after film removal of an inspection target in a process substrate in which a blank mask having a film to be inspected or a production intermediate thereof and a film on which an inspection target has been removed is formed; Illustrating.

Fig. 2 is a graph showing the amount of change in bending (ΔTIR) obtained in Example 1.

Claims (8)

A method for inspecting a blank mask or a manufacturing intermediate thereof, which is a method for inspecting a blank mask or an intermediate thereof by evaluating stress of a film constituting a blank mask or a manufacturing intermediate thereof, characterized in that the blank light is When the cover or the intermediate system for manufacturing the same is processed into a mask, the other film is further laminated and processed, and the film is applied to the film to be inspected by laminating the other film. After the energy of the energy is previously applied to the film of the inspection object, it is processed by the steps including the following (A), (B), and (C): (A) measuring the blank mask of the film having the stress inspection object or manufacturing intermediate thereof a step of removing the surface of the body, (B) a step of removing the film of the object to be inspected, and (C) a step of measuring a surface shape of the film-treated substrate from which the object to be inspected is removed, thereby obtaining a film before the film removal of the object to be inspected The surface shape of both the blank mask or the intermediate thereof to be processed and the processed substrate after the film of the inspection object is removed, and by comparing the surface shapes, the film of the inspection object is evaluated. Stress. The inspection method according to the first aspect of the invention, wherein the film to be inspected is one or more selected from the group consisting of a phase shift film, a light shielding film, an etching mask film, and an etching stopper film. The inspection method of claim 1, wherein the blank mask or the intermediate system for manufacturing thereof is subjected to the above-mentioned manufacturing process The blank mask or the film of the intermediate in which it is produced is obtained by the step of imparting energy. According to the inspection method of the first aspect of the invention, after the other film is laminated on the film to be inspected, energy is applied to the film to be inspected by applying energy to the processing of the other film. The inspection method of claim 1, wherein the other film is a photoresist film. The inspection method according to any one of claims 1 to 5, wherein the evaluation of the stress of the film of the inspection object is performed by removing the blank mask before the film of the inspection object or the intermediate of the manufacturing intermediate thereof. The surface and the outermost surface of the processed substrate after the film of the inspection object was completely removed from the blank mask or the intermediate of the inspection, and the following evaluation was performed: (1) Each surface was measured by a surface shape measuring device to obtain the XYZ of the outermost surface. 3D coordinate data, (2) the coordinate data obtained from each of the outermost surfaces, the least square plane of each outer surface is obtained, (3) so that the outermost surface coordinate of the blank mask or its manufacturing intermediate is between the least square plane The relative position and the relative position between the outermost surface coordinate of the processed substrate and its least square plane are fixed, so that the coordinate and the least square plane are configured in the following manner: (i) the two least square planes are located at XYZ On the XY plane of the three-dimensional imaginary space, (ii) the center of the area of the outermost surface of the blank mask corresponding to the least square plane of the former or the intermediate body thereof The center of the region corresponding to the outermost surface of the processing substrate of the least square plane is located at the origin, and (iii) the four corners corresponding to the two regions corresponding to the outermost surface are removed to correspond to the film of the inspection object. In the front and rear manner, the diagonal directions of the two regions corresponding to the outermost surface are aligned and overlapped, and (4) the coordinates of the outer surface of the blank mask or the intermediate body thereof are formed within the coordinate data range of the above configuration. And the coordinates of the coordinate of the outermost surface of the processed substrate whose coordinate values of X and Y are the same, and the Z value (Z ₁ ) of the outermost surface of the blank mask or the intermediate body thereof is determined and the outermost surface of the processed substrate is obtained. The difference between the Z value (Z ₂ ) (Z ₁ -Z ₂ ), (5) the sum of the absolute value of the maximum value of the Z value (Z ₁ -Z ₂ ) and the absolute value of the minimum value as the bending variation The surface shape is compared by the amount of change in bending. A method for judging the merits and demerits of a blank mask or a manufacturing intermediate thereof, characterized in that the advantages and disadvantages of a blank mask or a manufacturing intermediate thereof are determined by the amount of bending variation obtained in the inspection method of claim 6 of the patent application. The method for judging the merits and demerits of the seventh item of the patent application is such that the value of the bending change is 50 (nm) / L / 152 (mm) or less (only L represents the length of the long side (mm) of the transparent substrate). Considered as a good product.